The Trump administration is already moving to take Americans’ private property to build the wall Mexico isn’t paying for.

“The freedom to own and protect one’s private property is foundational to our country. Congress must fight to protect the private property rights of Americans and reform the use and abuse of eminent domain,” observed Rep. Jim Sensenbrenner (R-WI) in March as he reintroduced his Private Property Rights Protection Act — a biennial rite for the veteran Congressman since 2005. Days later, at a House subcommittee hearing, Chairman Steve King (R-IA) boasted of the bipartisan support the bill enjoys and noted that a 2005 survey found “public support for limiting the power of eminent domain is robust and cuts across demographic and partisan groups.”

Eminent domain reform has been a popular rallying cry among Republicans — who explicitly endorsed Sensenbrenner’s bill in their 2016 platform — and libertariangroups since a controversial 2004 Supreme Court ruling affirmed the rights of government authorities to take private property with even a modicum of public purpose.

Now the Trump administration prepares to launch another major push to take private property: This time, the seizures will take place along the southern border to facilitate the construction of a border wall.

Throughout the 2016 campaign, Trump over and over told cheering supporters that the entire cost of that wall would be borne by Mexico, but he is already asking U.S. taxpayers for the first $1.5 billion. Senate Majority Leader Mitch McConnell (R-KY) has flatly dismissed any notion that the money will someday be reimbursed by the neighbors to the south. The Department of Homeland Security’s initial estimate for the total cost: as much as $21.6 billion.

Part of that estimated cost includes payments to landowners for seizing their property to facilitate building the wall.

While property rights experts told ThinkProgress that these sort of takings would almost certainly be legal (even with a reform like the Sensenbrenner bill), they say that the constitutionally required “just compensation” due to the landowners could significantly increase the already exorbitant projected costs and bring significant harm to homeowners and ranchers who live in its path.

The Fifth Amendment is perhaps best known for protecting the rights of accused criminals, but it also contains an important property rights protection. No private property, it guarantees, shall “be taken for public use without just compensation.”

In other words, if the government needs to take part of your back yard to build a water main — or needs to bulldoze your house to construct the Bevingford bypass — it can do so, but it must pay you whatever the land is worth.

The $21.8 billion estimated cost of the wall, given the vagaries of land compensation, is just a starting point. The ultimate cost could be even higher than those estimates if courts decide the government’s offers to reimburse landowners are too low. Legal fees plus increased payments to those whose property has been taken could really add up.

“A border wall is a public purpose, even if not a wise one.”

The government is almost certainly within reason to invoke this right when it comes to building a border wall. In the 2004 Kelo v. City of New London case, a local government body decided to condemn the Connecticut home of Susette Kelo so that a private developer could proceed with a comprehensive redevelopment plan (a plan that ultimately never came to fruition when the developer’s funding fell through). A 5 to 4 majority of the Supreme Court held that “over a century of our case law interpreting” the Fifth Amendment dictated that even this was legally a “public purpose.”

“A border wall is a public purpose, even if not a wise one,” explained John Echeverria of the Vermont Law School, a property law expert. “If we’re dumb enough to want to build a wall, if the government of the United States makes a decision to build a wall — and I’d be sad if they did — I don’t doubt the eminent domain power is available to make that decision.”

But the other half of that Fifth Amendment clause does merit some examination, said Vanderbilt Law School Professor Emeritus James W. Ely Jr.. “The controversy won’t be on public use side,” he observed, “but on the just compensation side. Some of the land owners, possibly [Native American] tribes, may challenge the government’s determination of just compensation.”

Such a challenge could court trigger litigation. “The just-compensation formula goes by market value,” he added, which is “not always easy to determine, especially in case of unwilling sale.”

The first condemnation letters go out

In January, before Trump had even been inaugurated, the seizure process began for some Texans with land along the Mexican border. The Texas Observer reported that on January 12, a “Declaration of Taking” was mailed to Maria Flores, one such property owner by the Justice Department, informing her that the United States “is acquiring property along its border with Mexico in order to construct a fence and related improvements designed to secure the border, as required by the Secure Fence Act,” a 2006 law that required reinforced fencing along parts of the U.S.-Mexico border.

That letter offered the Flores “just compensation”—$2,900 for her 16-acre property. The land that had been in the family for five generations and is currently used for cattle grazing. Even if she rejects the offer, the government can still take the land for an amount to be determined. “It’s scary when you read it,” the owner’s daughter Yvette Salinas told the Observer. “You feel like you have to sign.” Salinas added that while her family and town do not want Trump’s wall, they don’t much like the idea of getting sued by the U.S. government, either.

Congressman Henry Cuellar (D-TX) represents a district that includes much of the Texas-Mexico border and is a vocal critic of the proposed wall. In a phone interview, he noted that many of the people in his district live on property their ancestors acquired in the 1750s Spanish land grants.

“The federal government has a lot more resources than a lot of people down here on the border,” he noted. “They will raise cattle, the water at the Rio Grande is very important to them. If you put a fence, you know what’s gonna happen, not only to wildlife but to the cattle.”

One constituent, Cuellar added, buried his father — a World War II veteran — near the river, on the family’s property. The plan for the wall would put the structure in between the man’s home and his father’s burial site.

“Let’s assume they can come up with a ‘fair price’ for this. How do you compensate him?” he asked rhetorically. “We’re gonna cut you off from the grave-site of your own father on your own property? How do you compensate somebody for that type of situation?”

Unjust compensation

But it’s not just Democrats who have concerns about this process. James Burling is vice president of litigation at the Pacific Legal Foundation, a California-based libertarian law non-profit that works for limited government and property rights. And he is not the least bit surprised that the government appears to be low-balling property owners along the border.

“There is a long history of the federal government under-compensating rural landowners and they have done so deliberately and underhandedly,” he posited. “When you look at the Department of Justice, the third word is a misnomer.”

While no one has contacted Burling yet about eminent domain actions to take their property to facilitate Trump’s wall, he expects problems going forward. “If the federal government is going to play the same game they’ve traditionally played, they’re going to offer low-ball offers to landowners hoping they’ll get them to agree without benefit of counsel.”

Those that do not accept the initial offers could see a lengthy court battle. But while that could delay the compensation process, it might not actually delay the wall.

Quick takes

Like any other legal proceeding, the process of nailing down “just compensation” can be drawn out. Rather than allow that process to delay the construction project, several states and the federalgovernment have passed “quick take” legislation to bypass that process.

Indeed one piece of the U.S. code specifically grants this sort of quick-take authority to the U.S. attorney general, allowing them to begin condemnation proceedings within 30 days in cases where the owner and the landowner cannot agree on a reasonable price, in cases where the land is “adjacent to or in the vicinity of an international land border,” and when the “Attorney General deems the land essential to control and guard the boundaries and borders of the United States against any violation of this chapter.”

Vanderbilt Law’s Ely explained, “If you can convince a court it’s necessary and imminent to take property, a court can approve the taking and let the just compensation be resolved down the road.” This, he notes, is can be a vehicle for abuse on the part of the government entity.

While money would be deposited into a holding fund for later, nothing would go to the property owners until the situation is resolved — meaning they would have to pay for their moving expenses and a new home now and hope to get paid a fair amount later. “It puts the landowner in an even worse spot — [he or she] has no compensation to get off land. This might force them to accept [the government’s] offer, whether they want it or not.”

While some have speculated that eminent domain compensation challenges could significantly delay the wall’s construction, eminent domain expert Gideon Kanner noted on his Gideon’s Trumpet blog that these people likely have “never heard of the Declaration of Taking Act, or of the rule that the feds need not pay first before taking the subject property. To say nothing of the cost of litigation that such landowners would have to bear while all that litigation goes on.”

An expensive process

The bottom line, experts agree, is that the federal government can use eminent domain to take the land, but the legal costs and ultimate payments could mount for the administration.

“If the federal government makes them an offer they don’t agree with, it can potentially take a long time to get the amount of compensation the landowners thinking are due,” said the Pacific Legal Foundation’s Burling. “It’s not really rocket science: landowners are entitled to compensation and government is entitled to undertake infrastructure projects, even if people don’t want them. The government’s gonna try to pay less than the owners think property is worth, and they’ll fight for a while.”

Lawyers who do all this work on behalf of the federal government also will not be cheap. According to the Texas Observer’s reporting, Trump’s initial budget calls for 20 Department of Justice attorneys to focus exclusively on border wall-related eminent domain work.

“If Trump wants to focus on a fence, he needs to focus on the White House fence.”

And the cost is not just financial. Vermont Law’s Echeverria pointed out that “the political cost” of building the border wall “will generate all sorts of heart-rending stories of people having their property taken away, cut into pieces. The human costs of eminent domain are going to be visible.”

And that is Rep. Cuellar’s concern. “Besides just compensation you run into other issues: the environment, the treaty with Mexico,” he said. “But the main thing — most of this land is private property. For many years, we’ve always defended private property.” The wall, he added, “is a 14th century solution to a 21st century problem.”

And, he quipped, “If Trump wants to focus on a fence, he needs to focus on the White House fence. A lot of jumpers have gotten in and if people jump the fence in one of the most secure places in the whole world, we know what’s gonna happen in some rural area.”

For his part, Trump himself has vowed to bring the cost of the wall “way down” through his amazing negotiating skills. But if he plans to save money in this area, it would mean convincing these property owners to settle for even less for their homes, ranches, and properties.

Of course there is one way the Trump administration could avoid taking any Americans’ land by eminent domain: Secretary of the Interior Ryan Zinke suggested to Politico last week that perhaps portions of the wall could simple by built in Mexico.

This story has been updated to correct the name of Vermont Law School.